An AC servomotor is a motor used for an AC servo equipment. Generally, the AC servomotor is a two-phase induction motor, and a stator is configured of a reference field winding and a control field winding orthogonal to each other.
In addition, since the two windings of the AC servomotor have a phase difference of 90o, a rotating magnetic field generated by the phase difference rotates a rotor, and a torque is proportional to the magnitude of a control signal voltage and linearly decreases according to the speed.
In addition, although both a BrushLess DC (BLDC) motor and a Permanent Magnet Synchronous (PMSM) motor have the same basic structure of three-phase, there may be a difference in that whether a back electro motive force (Back EMF) is a trapezoidal wave or a sinusoidal wave.
A coil is wound in a concentrated winding method in the BLDC motor and in a distributed winding method in the PMSM motor.
In the case of the PMSM motor which is used for most of industrial servomotors in these days, a rotating part (rotor) is made of a permanent magnet, and a coil of three-phase is wound a part which provides current (stator). Here, since the stator is three-phase, if a power of three-phase is supplied, a rotating magnetic field is generated inside the PMSM motor, and the rotor (magnet) rotates in synchronization with the rotating magnetic field.
Since the PMSM motor does not have a brush, the most outstanding disadvantage is being free from abrasion of a brush, and as a space vector control technique is commercialized, the PMSM motor substitutes for an existing DC motor and is controlled in a method similar to that of the DC motor.
In addition, the PMSM motor may directly control the torque and exhibits excellent performance in speed control, position control and the like.
On the other hand, a lot of studies on the BLDG motor are under progress recently, and the BLDC motor is frequently used for controlling high torque and high speed, whereas the PMSM motor mainly used for a precise servo is in the middle of commercialization. Specifically, the BLDC motor may be used to control the speed of a missile, a belt of a treadmill or the like.
Basically, a processor is used to control the industrial AC servomotor, the BrushLess DC (BLDC) motor and the Permanent Magnet Synchronous (PMSM) motor described above, which are commonly used for a production and service robot and an automated system.
The processor performs a function of analyzing a command received from a user, performing an operation corresponding to the command and outputting a result of the operation, and a device which integrates an operation device, an analysis device and a control device into a component like this is referred to as a microprocessor or a processor.
Since a motor control module using such a processor separates a motor control means and configures as a system-on-chip SoC, load on the processor is lowered, and performance of the system is improved.
On the other hand, a general purpose processor such as a DSP is used to control and operate the industrial AC servomotor, the BLDC motor and the PMSM motor of the prior art, and an algorithm for driving the motors is implemented as firmware and performs control and operation at every sampling time.
At this point, it is programmed to perform a control and operation algorithm function by setting a timer interrupt service routine (a timer ISR) in order to perform an operation at each accurate sampling time.
However, if a controller based on firmware is designed in the technique of the prior art as described above, a time for performing a control and operation function is restricted by the performance of a processor used for the control and operation.
For this reason, a high-speed processor should be used in order to enhance control performance, and this will lead to increase of a unit price, and since a developer should implement a controller and a filter used for operation, difficulties in developing a motor control system will be increased, and thus a solution for this problem is required.